Rafter calculating and plotting attachment for squares



Feb. 1o, 1925.

J. C. BROWN RAFTER CALCULATING AND PLOTTING ATTACHIINT FOR SQUARBS Filed Oct. 25, 1922 3 Sheets-Shea*l 1 3mm/it J. C. rau/n will Feb; 10.1925. 1,526,114

J .-'cv.g-BRo'wN METER CALCULATINGAND PLOTTING ATTAcHuzNTrox sQUARns Filed oct. 25, 1922 s shets-sheet 2 Feb. 10, 1925. 1,526,114

J. c. BRowN RAFTER CALCULATING mi) PLoT'rING ATTAGHIENT tonrjfsUARns 'Filed oct. 25.` 1922 s sheewstnget s Patented F eb. 10, 1925.

PATENT OFFICE.

JOHN C. BROWN, OF ATLANTA, GEORGIA.

RAFTER CALGULATING AND PLOTTING ATTACHMENT FOR SQUARES.

Application filed October 25, 1922.

To all whom it may concern:

Be it known that I, JOHN C. BROWN, a `citizen of the United States, residing at Atlanta, in the county of Fulton and State of Georgia, have invented certain new and useful Improvement-s in a Rafter Calculating and Plotting Attachment for Squares; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a rafter calculating and plotting attachment for squares and constitutes an improvement of that `form disclosed in Letters Patent of the United States No. 1,248,67 8, issued to me on October 16, 1917 and entitled Combined square and bevel for ascertaining the length of rafters etc.

The present invention aims to provide a tool of this character which accomplishes `the function of that set forth in said patent in an improved and more efficient manner, which attains various additional functions whereby it is capable of more general use and is more advantageous, to provide a construction which particularly includes a novel center point means, means whereby the common rafterblade and hip rafter blade are individually usable with sections of the stock and said blades avoid such projections as will interfere with individual use, novel means for attaching the stock to the square, novel extension means and calculating data for the blade, a construction in which the parts are connected together so that the axis of the blades will not be obscured, a novel connecting means for the stock to the square and a novel level attachment for connection with either section of the stock and either' rafter blade if desired.

The invention consists in the construction, combination and arrangement of the parts hereinafter described and illustrated in accompanying drawings from a consideration of which various additional objects and advantages will become apparent; it being understood that changes in the form, proportions, size and details of construction may be resorted to within the spirit and scope of the invention.

In said drawing Serial No. 596,904.

Figure 1 is a View in elevation showing the lmproved attachment assembled and clamped to a square;

Figure 2 is a view taken on the line 2--2 of Figure 1;

Figure 3 isan elevation of the hip rafter blade.;

Figure 4 is an end view of said blade;

Figure 5 is a view of said blade looking at the upper edge thereof relative to Figure 3;

Figure 6 is a side elevation of the common rafter blade;

Figure 7 is a view of said common rafter blade looking at the top of Figure 6;

Figure 8 is a side elevation of the stock;

Figure 9 is an edge view of said stock looking toward the inner or active edge;

Figure 10 is an edge view of said stock looking to the outer edge thereof;

Figure 11 is across sectional view on the line 11-11 of Figure 8;

Figure 12 is a cross sectional view on the line 12--12 of Figure 8; Y

Figure 18 is a cross sectional view on the line 13-13 of Figure 8;

Figure 14 is a cross sectional View on the line 14-14 of Figure 8;

Figure 15 is a cross sectional view on the line 15-15 of Figure 8; y

Figure 16 is a side elevation of the stock reverse to that shown in Figure 8;

Figure 17 is an elevation of a level attachment; Y

Figure 18 is an edge view of said level attachment;

Figure 19 is a cross sectional view through the stock showing said level attachment fasteled for use with one of the rafter blades, an Y Figure 20 is a cross sectional view similar to Figure 19 but showing the attachment fastened for use with one of the rafter blades.

Like reference characters designate like or similar parts in the different views.

Referring specifically to the drawings, 1 designates an ordinary square having the usual short arm 2 and long arm 3. My improvement, by means of a stock 4 is adapted for adjustable and rigid attachment to the arm 2 and said stock adjustably mounts a common rafter blade 5 and a hip rafter blade 6. The rafter blades 5 and 6 are adapted for relative adjustment, coaction and function in the manner set forth in said Letters Patent 1,243,678. The square 1 is preferably graduated as shown by the calibrations or indications at 7, and along the blade 3 a plurality of indexclips 8 are slidably mounted and adapted to indicate the run of the common rafter and the run of the corresponding hip rafter, respectively, being fastened in adjusted positions in any suitable manner and for instance by means of small cam levers 9 pivoted at 10 to the clips and directly engageable with and to bind against the adjacent longitudinal edge of said arm 3.

Referring specifically to the stoclr 4, its offset connection with respect to the blade 2 affords a handle and it is preferably made in outer sections or plates 11 and 12 and an intermediate section 13 consisting of plates 14 and 15. Plate 14 has a dove-tail rib 16 projecting therefrom which enters a correspondingly shaped recess 17 of the plate 15 intermediate ribs 18. As best shown in Figures 9 and 10, the end lug or flange 19 isprovided on the plate 15. By reason of the construction of said plates 14 and 15, they are slidably connected together and movement of one relatively to the other is limited by said flange 19. ln addition suitable openings 29 are provided thr ugh the ribs 16 and 18 so as to register when the flange 19 abuts the adjacent end of plate 14 in order to receive a removable locking pin 21. (See Figure 13.) This pin 21 may be individually used as a marker or scriber. The adjacent faces of the plates 11, 12, 14 and 15 are cut away to provide recesses 22 and 23. Concentric arcuate ribs 24 an( 25 extend into the recesses 22 being integral with the plates 11 and 14 respectively and entering corresponding grooves or recesses 26 of the blade 6 to thus serve to pivotally mount said blades 5 and 6. Plate 11 may be secured to the section 14 against displacement in any suitable manner for instance by means of a set screw 27 which extends loosely through an opening 281m section 11 and into a screw threaded opening 29 in section 14. lt will be seen therefore that the hip rafter blade 6 is accommodated in the recess 22.

The common rafter blade 5 is accommodated in the recess and extending integrally from the plates 12 and 15 as at SO anc 31 respectively are ribs concentric with the ribs 24 and and disposed in recesses 32 in said blades 5. Plates 12 and 15 are fastened together in any suitable manner as by means of a set screw 33, similar to set screw 27, passing loosely through an opening 34 in section 12 and into a screw threaded opening 85 in section 15.

ln order to guard against relative turning of the different sections of the stock 4, dowel pins 36 and 37 may respectively extend from the plates 11 and 15 into corresponding recesses 38 and 39 in the plates 14 and 12.

As in my said Patent 1,243,678, the upper end edges of the sections of the stock are arcuate as shown and adjacent the same the outer sections 11 and 12 are preferably reduced as at 39 and provided with various graduations.`

The axis of rotation of the blades 5 and 6 is indicated by the center or point 39:1 and adjacent the same the different sections of the stock 4 are cut away as at 40 so as to particularly provide a radial line 41, extending at a right angle to the blade 2 and adapted to serve as an indicator for coaction with the indications of said blade. The various ribs 24, 25, 3() and 31 are concentric with the center 39 as will be understood.

As shown in the drawings a clamping arm 42 may be used to clamp to the square as when the device is to be used with one or both of the blades 5 and 6 and it is adapted to extend from the section 12 and have a lug 43 overlap the inner edge of the blade 2 so as to clamp said blade 2 between said lug 43 andv section 11. Clamp arm 42 is screw threaded in an elongated tubular nut turnably mounted in the section 11 and held in place by means of an annular flange projecting from section 11 and upset into a corresponding groove 46 in said nut. Clamp arm 42 is slidably and turnably mounted in a recess 47 in section 11 which is laterally enlarged as at 46 so as to normally retain lugs 43 therein, that is when the stock is not attached to the square 1. Said nut 44 has a free end at -19 which projects beyond section 11 to form a linger grip or manipulating portion.

As in my said Patent 1,243,678, a. connectingI lever or link is employed at 59 whereby `he blades 5 and 6 are connected together so as to move simultaneously when one of them is adjusted. Lever 59 is pivotcd on a screw 51 at the shank 52 thereof, said shank loosely passing through the lever and being threaded into the section 11 as at 53. A suitable bolt- 54 extends from the lever 5() and is suitably connected to the blade 6. preferably passing through a slot there' of. ySaid slot 55 is preferably open at the free end of said blade 6 so that the blade G may be readily disengaged from the bolt 54 without removing the bolt or its nut. bolt at 56 extends from the lever 50 at the opposite end to bolt 54 and tl rough a slot 57, of the blade 5. This slot 57 is preterably laterally enlarged as at 58, sce Figure 6, so that the head or nut of the bolt 56 ma;r pass through the enlargement thusenabling the blades 5 to be deached from the 'bolt 56 without necessitating removal of bolt56 or its nut.

As is obvious, the blades 5 and 6 maybe suitably calibrated or contain indications as shown to facilitate measurement and they may also be of any approved eXtensible construction. The blade 6 particularly has an auxiliary blade 59, particularly see Figure 6, which is slidably connected to blade 6 by means of a suitably shaped rib extending from blade 6 and` into a suitable groove or recess corresponding thereto. Auxiliary blade 59 may be secured in adjusted position in any suitable manner such as a conventional clamp as at 61 and corresponding in construction to the cam clamp 9, and being pivoted as at 62 to the extension 59.

On the blade 5 as shown at 64 in Figure 6, suitable data` for cooperation with the sections and their graduations is provided.

Thedi'tferent sections 11, 12 and 14 may be recessed as at 65 in order to afford finger grips or holds. 1n the said recesses 65 of the outer sections 11 and 12, the heads of the set screws 27 and 33 are accommodated without projection beyond the sides of said sections. j

11s best shown in Figure 16, a blade 66 is angularly and slidably disposed in a recess 67 in the outer surface of section 12. Plate or bla-de 66 has an elongated slot 68 through which a fastening screw 69 passes and which slot at 70 is enlarged to facilitate removal of the blade 66 without removal of the screw 69.` Extending from the blade 66 is a center' or point 71 which is normally adapted to occupy a recess 72 in plate 12 extending from the base of slot 67. The slot 68 permits removal and reversal and reattachment of blade 66 to set screw 69 so that the `point 71 will extend at a right angle from the section 12 as shown in Figures 9 and 10, for penetration into a chart, or board and serve as a center from which the stock or sections thereof, with either or both bla-des 5 or 6 attached, may be swung as a center for calculationsbased on the calibrations or graduations of said blades. 1n additiomthe blade 66 may be separated from the section 12 as understood so that it may be individually used as a marker or scriber.

ris a result of the construction shown, blades 5 and 6 may be used as in my said Patent 1,248,678. In addition, the blades may be individually used as squares er bevels by removing the pin 21 and then disengaging the sections 144 and 15 by sliding` movement. It being clear that the blades 5 and 6 are capable of swinging movement from the center 69 and that the parts are so arranged and proportioned as to leave said center always open to view and consideration in connection with the various graduations of the parts.

As particularly shown in Figures 17, 18, 19 and 20, ay suitable levelling attachment maybe associa-ted with the invention. This attachment may consist of a block or stock 7 5, of general shape similar to the stock 41 having a dovetailed rib 76 projecting from one side thereof and a dovetail recess 77 projecting from the other side thereof.

The square end of stock is cut away or recessed at 78 to accommodate the flange 19 and said end has a flange 79 to overlap plates 14 instead of and similarly to flange 19 when the stock 75 is used as in Fig. 19. A spirit level is provided along the longer straight edge of stock 75 consisting of the bubble tube 8O which is disposed in a recess 81 and which bubble tube is protected by a. plate 82 disposed over the' same and fastened to stock 7 5 'as bv means of screws 83. Plate 82 is slotted at 841 so that the bubble tube may be viewed. Y

In using the attachment or stock 75, and as particularly shown in Figure 19, the rib 76 is slidably received in the recess 17. Rib 76 and ribs 85 on opposite sides of recess 77 are provided with slots or recesses 86 which register with the slots or recesses 20. Through such registering slots or recesses, a pin 21 is passed so as to thus rigidly connect the stock 75 to the plate 15. Such connection is detachable in order that the stock 75 may be removed at desirable times for individual use as a spirit level.

As shown in Figure 20, stock 75 may be secured to plate 14 by disposing rib 16 in recess 77 and then passing a pin 21 through recesses 86 in rib 16 and ribs 87.

As merely one practical embodiment has been illustrated and described, it is to be understood that changes in the 'details may be resorted to provided they fall within the spirit and scope of the invention.

I claim as my invention :k

1. An instrument of the class described in combination with a square, a stock, a blade pivoted to the stock, a clamp arm having an offset lug to overlap the square, the stock having a recess in which said lug is normally accommodated, an elongated nut turnably mounted in the stock and threaded to said arm, inter-engaging means between the stock and nut to prevent displacement of the latter and the nut extending beyond the stock to facilitate manipulation.

2. An instrument of the class described having coacting blades, a pair of plates pivotally mounting each blade, means individually connecting the plates of different pairs together', and means to separably connect the pairs of plates together and in superposed relation.

8. An instrument of the class described having coacting blades, a pair of plates pivotally mounting each blade, means to separably and means individually connecting the plates of the different pairs together, and means to separably connect the pairs of plates together and in superposed relation.

Ll. An instrument of the class described having coacting blades for joint use in substantially superposed relation, stock means connected to each blade, and means to separably connect the stock means together in superposed relation.

5. An instrument of the class described having c acting blades, a pair of plates pivotally mounting each blade, means separably connectingthe plates of each pair together, one of the plates of one pair having recess, one of the plates of the other pair having a rib to extend into said recess, and a locking pin to pass through said rib and recess.

(i. An instrument of the class described having coacting blades, a pair of plates pivotally mounting each blade, means separably connecting the plates of each pair together, one plate of one pair having a dovetail recess, and one plate of the other pair having a dovetail projection to extend into said recess.

7. An instrument of the class described havinga stock, a blade extending therefrom, said stock having a recess receiving` said blade, the blade having concentric recesses in opposite sides thereof, the stock having ribs extending therefrom and into the recesses of the blade to pivotally mount the blade, said stock being sectional, and fastening means for the sections whereby the blade may be clamped rigidly thereto or released for pivotal movement.

8. An instrument of the class described including a stock, a plurality of coacting blades operable from substantially the same axis, said stock being sectional whereby it has separable parts 'for separation and individual use for the different blades, and means separably connecting the blades and sections of the stock together and for unitary movement.

9. An instrument of the class described including a stock, a plurality of blades, said stoel; being sectional whereby it has separable parts for separation and individuality for the different blades, means separably connecting the blades together and for unitary movement, a lever to effect simultaneous movement of the blades, a pivot for the lever, on the stock, and fastenings for the lever engaging the blades.

10. An instrument of the elass'described including a stock, a plurality of blades, said stock being sectional whereby it has separable parts for separation and individuality for the different blades, means separably connecting the blades together and for unitary movement, a lever to effect simultaneous movement of the blades, a pivot for Laetrile the lever on the stock, fastenings for the lever engaging the blades, leach blade having a slot to receive said fasteningsand said slotsy being of'a shape to permit detachment of the blades over the heads of the fastenings;

ll. An instrument of the class described in combination with a square, a stock, means on the stock to clamp it to the square, a plurality of blades pivoted to the stock for coaction with the square, said stock having a plurality of plates, one of the blades extending intermediate said plates, said plates and last mentioned blade having interengaging concentric grooves and projections to pivotallb7 mount the'blade, a screw to secure said plates together', a pin extending from one of said plates into the other plate, a second plurality of plates, the other blade being disposed intermediate the second plurality of plates, the second mentioned plates and last mentioned blade having interchanging concentric ribs and grooves between them to pivotally mount the last mentioned blade, a screw to secure the second mentioned plates together, a pin extending from one of the second mentioned plates into the other second mentioned plate, one of the secondmentioned plates having a recess to receive said rib, and a pin passable through said recess and rib.

l2. n instrument of the class described having a plurality of blades, a stock having outer sections and a plurality of intermediate sections pivotally mounting said blades, one of the intermediate sections having a projection, the other intermediate section having a recess which said project-ion tits; and a flange on one of the intermediate sections abutted by the other intermediate section.

13. An instrument of the class described having a stock, a blade extending therefrom, a centering blade reversably disposed on said stock, and said centering blade having a point extending therefrom.

la. An instrument of the class described having a stoclr, a blade extending therefrom, a centering blade reversably disposed on said stock, and said centering blade having a point extending therefrom, the stock having a recess to receive said point in one of the positions of said centering blade.

l5. An instrument of the class described having a stock, a blade extending therefrom, the stock having a recess, a center'- ing blade slidably mounted in said recess, said centering blade having a slot therethrough provided with an enlargement, a. fastening passing through said slot and engaging the stock to provide for separable and reversable connection of said centering blade, a point on said centering blade, and the stock having a recess extending theicfrom to normally receive said point.

16. An instrument of the class described consisting' of a stock having a point, a blade pivoted on said stock7 said stock having a Wall passing through the axis of the blade to serve as an indicator, a centering blade reversably connected to the` stock, said blade in one of its positions having its point disposed coincident with the axis ot the rst mentioned blade, and in its other position being removed therefrom.

17. An instrument of the class described having blades, stock means separably connecting said blades and provided With a normally engaged projection and groove, and an auxiliary tool for disposition in the stock having' a groove to receive said projection and a projection to enter the first mentioned groove.

18. An instrument of the class described having blades, stock means separably connecting said blade and provided with a normally engaged projection and groove, and

an auxiliary tool for disposition in the stock having a groove to receive said projection and a projection to enter the first mentioned groove7 and pins to connect the auxiliary tool to the stock.

19. An instrument of the class described having' blades, stock means separably connecting said blades and provided with a normally engaged projection and groove, and an auxiliary tool for disposition in the stock having a groove to receive said projection and a projection to enter the first mentioned groove, and pins to connect the auxiliary tool to the stock, and said projection and grooves being of dovetail it'orrn.

In testimony whereof I aiiix my signature in presence of tvvo Witnesses.

JOHN C. BROWN.

Witnesses:

R. O. ADAMS, E. Q. RoDGERs. 

